Apparatus for exhibiting the fluorescence of fluorescent substances.



No. 883,653. PATENTED MAR. 31, 1908. W. G. LEVISON.

A APPARATUS FOR EXHIBITING THE FLUORE SGENGE OF FLUORESCENT SUHSTANGES. APPLIUATION FILED NOV- 29, 1905.

WITNESSES:

I I 715 v UNITED STATES PATENT oFrgioii.

' WALLACE GOOLD LEvIsoN, OF NEW YQRK, N. Y.

APPARATUS FOR EXHIBITING THE FLUORESCENCE OF FLUORESCENT SUBSTANCES.

' Specification of Letters Patent.

Patented March 31, 1908.

Original application filed May 1, 1903, Serial No. 150,323. Divided and this application filed November 29, 1905.

' Serial No. 289,698. a

To all whom alt may concern:

Be it known that I, WALLACE GooLn LEVrsoN, a citizen of the borough of Brooklyn, county of Kings, and city and State of New York, have invented a new and useful Afpparatus for Exhibiting the Fluorescence o Fluorescent Substances Applicable 'to 'Various Practical Purposes and the following is a description of my invention, such as 1 enable any one skilled in the art to which it belongsto make and use it, refer ence being made to theannexed half-size drawing of a fluoroscope, of.which the following 1s adescription;

Figure 1, is a' side view'of the right hand side. Fig. 2, is a cross section on the line 2, in=Fig, 1. 'Fig. 3, is a longitudinal section on the line 3, Fig. 2. Fi 4, is a perspective view of a cell to hold co ored liquids in which 2 india rubber is insoluble. It c'ontsists of two panes or plates of transparent material, (quartz, glass or other material as may be preferred, usually 3% x 4} photographic glass plates), separated by a frame cut from packmgrubber and cemented with plaster of pans, in a sheet brass frame; An opening a (Fig. 4), which may be closed with a cork permits the introduction of the colored iqluid em 10 ed'.

A n all t e gures,-like letters, indicate the same-parts. i V

Figs. 1, 2 and 3 represent alight pasteboard box. A is the body of an ordinary Xerav fiuoroscope which is provided with the usua handle B and chenille edged shield for the eyes at C. The X-ray screen is removed however, only the case bein used. D is an additional section which slips ti htly over the box A and is provided with a tlght fitting -4"o cover E. This section is provided with opposite openings in its two sides. The one on'the rlght'hand is indicated by'the dotted line a a Fig.1,is surrounded by stri s of half inchwood F,'F F forming a rab eted recess to permit the insertion of the block of wood Gwhich' is held in place by the springs 6 6 This block of wood is-perforated with a c rcular opening rabbeted to hold the fiat bottle H. This bottle, olished You both sides, is kept in its recess y the aluminium ring I hingpd to-the blockat J and secured by af-turn together with the bottle H may be removed bysimpl drawing it from under the springs v bb and t e cell'Fig.;4; sheets of blue glass, or

them in a spectrum, and the i lumination in this fluorescence. These constitute the larger utton K. The block of wood G sorted in its place, being retained by the springs b 6 Thus bottles or cells filled with any colored liquid desired or other colored screens may be employed at pleasure to cover the opening a. a. The opposite opening, on the left hand side of the case L shown in the section Figs. 2 and 3, must-be large enough to easily admit the hand. To this opening ta sleeve 'M made of flexible material, assue'de 6-5 kid, is attached by means of glue. Through the sleeve M, shown full length, in the section Fig. 2, and also in part han ing'belo w the case in Figs. 1 and 3, the han' and" wrist may be inserted. I Thus a mineral specimen, a gem, or any other object, may be held'in the hand within the box and turned-about at pleasure for examination on all sidesin the colored li ht admitted by the window and its screenT-l, Fig. 1.

N Figs.'2-and 3 is a window or paneof yellow glass or yellow stained gelatin coated lass which is held in place by agroove formed of strips of wood 0 c at .the' bottom, a rabbet formed of strips of wood 0 c at the sides and top and a in d attached to a s ring 6 Fi 3, which w en lifted allows-of t e remova of the window when desired. L

Fluorescent substances in common light usually present an insignificant aspect, but in a light capable of exciting their fiuorescence, which is not accompanied by other light acting to mask its efiect they are caused to appear in vivid and beautiful colors-of great beauty. Unfortunately no way =-1s known of subjecting such substances *toa strictly monochromatic light of-the particular Wave-fre uency desired Wholly unmixed with other light waves, exce t by placing any ordinary spectrum is so feeble that it excites only a'few ofthe more sensitivefluorescent substances at all strongly. But this method has served to determine that-it is certain. ofthe more refrangible waves from light sources (differing somewhat with different substances) but especially including 'cer-.. tain groups of wayes in the blue, violet and ultraviolet which are best adapted tojexcite I05 proportion of waves'in certain kinds of light f artificially produced. Thus, the lightfrom a high potentialelectri-cal discharge-in air or other gases across a spark gap-between-varioustermmalsforming part of a circuit connected with a Leyden jar or other condenser to form a sort of oscillator is articularly aprescence but in which there are also rays oflower refrangibility in such quantity as to predominate and'thus more considerably or even wholly mask the effects produced. Sources of such light are the are electric light especially between electrodes of iron, the magnesium light, condensed sunlight and finally the acetylene. gas light, each being less efficient, erhaps, in' the order named. All the above ights are more eflicient when condensed by suitable lenses and when the undesirable components of lower refrangi bility are more or less removed by ray filters,

' transmitting chiefly or only the desirable sirable.

quartz lenses should preferably be used and rays. Whether the masking eflect of the associated rays of low refrangibility is purely subjective or whether they reverse and so frustrate the activity of the rays of high refrangibility, their presence is equall unde- To condense the des1rab e rays,

to filter them from the undesirable rays they should be transmitted through suitable ray filters, such as colored materials, either in the form of solution in cells, referably of quartz, 'orspread in suitable vehicles as gelatin collodion or varnishes over the surface of plates or lenses, referably of quartz or transmitted through enses of colored vitrified quartz, which it seems robable will be eventually produced in avaflable quantities for the purpose. For all these ap liances glass may be used instead of quartz but to less advantage as it more largely arrests the desirable rays. Even with glass appliances, however, brilliant effects .may be produced. The ammonium sulfate of co per, which forms a blue solution, is about t e m'ost eifective ray filter for the urpose, although other colored solutions, t e colored solid materials above mentioned, and ordinary cobalt-blue and violet glass may be used in certain cases, with roper recaution to avoid misleading efects. en the undesirablerays from the four latter sources of light are thus removed by color screens the residual transmitted light compares favorably with that from -either of the sources previously mentioned and is eflicient in even a greater number of cases. But in all cases the incident light being itself partly reflected masks more or less the'fluorescent color developed and so 'afi'ects ight or wholly conceals the intensity and beauty of the effect produced. As the incident light 'thus reflected consists only of rays of higher refrangibility, while the fluorescent light pro.- duced consists. usually of rays of lower refrangibility, to obviate the masking efiect of the reflected incidentlight it is only necessary to examine the excited objects through a second ray filter which will not transmit the former but will transmit the latter rays. Such aray filter must have a so-called yellow color and may be a solution of bichromate or picrate of potash or other substance or ca- .nishes colored of a suitable yellow color and s read over or between surfaces of glass. In the latter case the cover glass may be cemerited to the colored glass with balsam and benzol and the whole edged with binding stri s for protection in the. usual manner.

photographic purposes are well, adapted for.

the eye-screens herein described. By means of the combination of these two screens, as

nary yellow glass, or'gelatin collodionor varhe color best adapted for the eye screen described, with light from any of the sources 4 mentioned, or of the. yellow eye screen alone, with some of them (such as the light of the sp'ark gap, the Geissler tube or the electric arc with iron terminals) fluorescence of all colors below the blue may be equally well detected and exhibited in objects of any size.'

Fluorescence of a blue color may be detected b using a violet colored solution or violet g ass for the light ray filter, without the eye screen but much of the color roduced may be due to residual incident blue, becoming evident throu h the removal of the violet by absorption. hus examined, the following series of minerals, either in specimens or pulverized and spread out as a coating to form fluorescentscreens may be mentioned as examples illustrating fluorescence of various colors below the blue.

Ralf-Ruby and rub corundum. Fluorescent s )halerite (e. 9. rom Cerro de Pasco, Peru.) .alcite, especially associated with VVillemite phosphorescent s'phalerite and some other minerals. 1

Orange.Arragonite, es ecially associated ,with, sulfur from Sicily and sulfids of metals in general. Calcite, especially associated with VVillemite from Franklin, N. J phosphorescent sphalerite and some other minerals.- Tribophosphorescent limestone (e. g; from VVahsatch Mts. Utah.) VVollastonite of some varieties.

Pin7c.Hexagonite (e. g. from Edwards,

N. Y., especially the white variety.) Calcite from Cerro de Pasco, Peru. Sombrerite' from the Sombrero Islands. Apatite, some varieties (e. g. from Haddam Neck, Conn.)

Yellotu.Pectolite and a large number of other minerals.

(1reen.-Autunite. (some varieties.)

Blue. Fluorite, in some varieties. Leucophanite in some varieties. Petalite in some varieties, and some other minerals.

Although only a series of minerals have been given and although for exhibition purposes the method and apparatus may be chiefly applied to minerals it is equally adapted to show fluorescence in other natural matcrials and dyed fabrics and papers and artificial preparations of numerous kinds. To apply this method practically for the exhibition of fluorescence, various arrangements or appliances may be employed according to the object in view. Thus fluorescent minerals or other specimens in museums may be kept on permanent exhibition if they be illuminated by a suitable permanent light filtered, if need be, through a blue or other suitably colored ray filter and observed by visitors through a suitable yellow or other colored eye screen, which may be the glass of the exhibition case, made of stained or colored glass or glass coated with colored varnishes as described. Under these circumstances they disclose a gorgeous beauty for the permanent exhibition of which no provision has heretofore been available and the presence or absence of which in gems serves admirably to distinguish them from ordinary imitations.

The case may be given the form of anordinary X-ray fluoroscope. As shown in the annexed drawing the eyes are shielded by a yellow screen removable at leasure and an opening at one side covere With the blue ray filter to admit the incident light concentrated by a lens if necessary, while through an opening on the opposite side. provided Willemite. Apatite with a door or a sleeve, specimens ma be inserted wlthm or wlthdrawn I at p easure.

This appliance is convenient for the examination of s ecimens by daylight as Well as by any arti cial light. I

For the detection of the presence or.ab--

sence of fluorescence in small mineral s eciused but the most convenient is that ofan acetylene bicycle lamp the lantern of which is provided with condensing lenses and a blue screen, and the object held near the focus of the li ht thus produced examined through a yel ow eye-screen as above described. Small specimens may also be ob- .served under the microscope, the eye-p1ece bein provided with a transparent ellow diap ragm or cover and the object il ummated by a suitable active light.

Having now described my invention, What I claim and desire to patent is, I

1. In an apparatus for examining fluorescent substances, the combination of a source of light, an inclosing box having a sleeved opening on one side and a removable cover for the introduction of the object to be examined, a ray filter upon another side to remove objectionable rays from the excltmg light and an eye shield provided with an eye screen to arrest unused .eflected rays of the incident rays substantially as described.

2. The apparatus descrlbed for facilitating the exhibition and examination of fluorescent substances by suitable wave frequencies consisting of a source of exciting ra s, a container, to inclose the specimens un er examination, rovided with a ray filter to arrest undesirable rays from the source and an eye screen to arrest any unused incident rays reflected from the object under examination.

3. In an apparatus for examining fluorescent substances the combination of a source of light, an inclosing box having a sleeved o ening on one side for the introduction of t e object to be examined, a ray filter upon another side to remove objectionable ra s from the exciting light, and an eye shie (1 provided with an eye screen to arrest unused reflected rays of the incident rays substantially as described. Y

WALLACE GOOLD LEVISON.

Witnesses:

F. DANA REED, F. L. SMITH. 

